class Solution {
public:
    int rob(vector<int>& nums) {
        int n=nums.size();
        return max(nums[0]+rob1(nums,2,n-2),rob1(nums,1,n-1));
    }

    int rob1(vector<int>& nums,int left,int right)
    {
        if(left>right) return 0;
        
        int n=nums.size();
        vector<int> f(n);
        vector<int> g(n);
        f[left]=nums[left];
        g[left]=0;
        
        for(int i=left+1;i<=right;++i)
        {
            f[i]=g[i-1]+nums[i];
            g[i]=max(f[i-1],g[i-1]);
        }
        return max(f[right],g[right]);
    }
};
